1. Field of the Invention
The present invention relates to a method, system, and program for managing volumes in volume groups.
2. Description of the Related Art
In certain computing environments, multiple host systems may communicate with one or more control units, such as an IBM Enterprise Storage Server (ESS)®, for data in a storage device managed by the ESS receiving the request. The control unit manages access to storage devices, such as interconnected hard disk drives through one or more logical paths. (IBM and ESS are registered trademarks of IBM). The interconnected drives may be configured as a Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID), Just a Bunch of Disks (JBOD), etc. The control unit may configure logical volumes that define regions of storage space in the storage devices the control unit manages.
To allow one host to concurrently submit and have pending multiple Input/Output (I/O) requests toward one volume, the control unit may assign alias addresses that point to a volume base address. The hosts may then have multiple I/O requests pending to a volume by using the base and alias addresses for that volume. The control unit may further assign both base volumes to a volume group and associate that volume group with one or more hosts, such that only hosts assigned to the volume group may access volumes whose volume base addresses are assigned to the volume group. Further, a host may only access alias addresses that point to volume base addresses assigned to the volume group to which the host is assigned. Current systems may further restrict the base volume to being in only one volume group.